February, 1921. 



The Canadian Field-Naturalist. 



29 



in tlie pools formed where the snow 

 melts ..." 



On June 1, 1920 Dr. A. G. Huntsman, 

 of Toronto, collected twelve specimens of 

 Enhranchipus gclidus in shallow sloughs 

 near Wetaskiwin, Alberta (near Edmon- 

 ton). One of these is an adult male, the 

 others are females, mostly adults, and with 

 ripe eggs. 



Together with the Streptocephalns col- 

 oradensis (see l)elow) these are the first 

 records of faiiy-slirimps from western Can- 

 ada. 



On the Canadian Arctic Expedition I 

 found in a large sliallow pond on top of a 

 ridge at Bernard Harbour, N.W.T., a num- 

 ber of fairy shrimps (both sexes) of a pe- 

 culiar species, {Artemiopsis Stefanssonii) 

 not known before. Another species (A. 

 huiujei Sars) is known from Siberia and 

 the New Siberian Islands. The new spe- 

 cies will be described and figured in detail 

 in the reports from the said expedition 

 (Vol, VII, Part G), so I need only give a 

 summary of my oliservations on it here. I 

 first observed it on October 6, 1915, in a 

 one foot deep pond which then had seven 

 inches of ice covering it, but in spite of 

 this the fairy shrimps were very active. In 

 size they were from seven to eleven mm. 

 long, the females being generally a little 

 longer than the males, but all were appa- 

 rentlj' adult and rii)e. They belong to the 

 group of fairy slirimps with eleven pairs 

 of progenital liml)s, and the male had its 

 claspers in the form of powerful, sickle- 

 shaped, terminal parts (with two spines 

 projecting some distances from their tips), 

 projecting from a swollen basal part, be- 

 sides somewliat spiral shaped i^rotruding 

 genital organs, while the female had a very 

 large elliptical egg-sack with olive-brown 

 eggs and a couple of curved processes pro- 

 jecting laterally from the dorsal side of the 

 genital segmejits. Especially do these fe- 

 male characters remind one decidedly of 

 Emhravchipus (jdidus, but the shape of the 

 male claspers and genitalia, together with 

 the absence of accessory copulatory organs 

 (frontal processes, etc.), distinguish them 

 at a glance. In color the males were paler 

 than the females, tlie latter were orange- 

 red-brown and transparent i)osteriorly. 

 When found these fairy shrimps were 

 mostly in coitu, the males holding the fe- 



males by their claspers dorsally just above 

 the egg-sack and aiding them in locomo- 

 tion. '•' Males not in copula would soon at- 

 tack one of the females, which were pre- 

 sent in larger numbers than the males, 

 and remain with her as long as copulation 

 lasted. I kept these fairy shrimps alive 

 for some days in a jar, but finally they 

 all died, nor dicl I have any success in try- 

 ing to rear the eggs during the winter and 

 next spring. What is apparently the ma- 

 tanauplii (2-3mm.) of this species I found 

 next summer (July 3, 1916) in the same 

 pond; at tliat date the Branchinecta palu- 

 dosa metanauplii were considerabh' larger, 

 so apparently the new species is somewhat 

 later (a couple of weeks) in its develop- 

 ment (hatching). On the other hand it 

 lasts longer in the fall, no Branchinecta 

 being met witli after tiie freshwater freezes 

 in September on this coast, while the other 

 fairy^ shrimp, as mentioned, was secured as 

 late as the end of the first week of October. 

 Owing to the shallowness of the pond, how- 

 ever, they probably would not live many 

 days longer, but be killed off when the 

 water froze to the bottom before tiie middle 

 of the month. I only found the new spe- 

 cies in the pond mentioned, and the locality 

 (Bernard Harbour) is the onh' one in 

 which it has been met with so far. In this 

 connection it is interesting to note that De 

 Dees (1910) says in his account of the 

 Siberian species (A. bungei) of the same 

 genus, that it apparently can withstand a 

 very cold water (about 1° Reamur), and 

 at least some of tlie specimens were secured 

 on October 10 (1886). This conforms re- 

 markably well witli my observations on tiie 

 ncAv Canadian arctic species {A. Stefans- 

 sonii.) 



Dr. A. G. Huntsman of Toronto has re- 

 cently sent me four adult (about 21/0 cm. 

 long) fairy-slirimps, one female, the rest 

 males, whicli lie collected on June 11, 1920, 

 in shallow sloughs, three miles northeast of 

 Medicine Hat, Alta. I have identified them 

 as Strcptocephalus coloradoisis Dodds, and 

 Prof. A. S. Pearse of the University of 

 Wisconsin has verified my determination 

 of this as of other uncommon Canadian 

 Phyllopods. These Streptocephaliis oc- 

 curred together with Lepidurus couesii. 



'•' Though the principal swimming was done 

 hv ihe female. 



